İlk commit: Stepstead backend (FastAPI)

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

models/database.py

@@ -0,0 +1,22 @@
+from sqlalchemy.ext.asyncio import AsyncSession, async_sessionmaker, create_async_engine
+from sqlalchemy.orm import DeclarativeBase
+
+from config import settings
+
+engine = create_async_engine(
+    settings.DATABASE_URL,
+    pool_size=10,
+    max_overflow=20,
+    pool_pre_ping=True,
+    echo=settings.DEBUG,
+)
+AsyncSessionLocal = async_sessionmaker(engine, expire_on_commit=False, class_=AsyncSession)
+
+
+class Base(DeclarativeBase):
+    pass
+
+
+async def get_db():
+    async with AsyncSessionLocal() as session:
+        yield session